Our approach to the study of the human disease, Coal Workers Pneumoconiosis (CWP), is to determine the response of mammalian cells in culture to coals from mines where the workers show different prevalences of CWP. Cell growth is inhibited more by coal obtained from mines where miners show the highest incidence of CWP. In this phase of our project, we are attempting to employ in vitro techniques that can be more easily extrapolated to the whole animal and man. There are several cellular responses that can be determined in cultured mammalian cells that appear to parallel responses of the whole animal. The connective tissue response is one of these. Collagen synthesis does not appear to be stimulated by exposure to coal leachates while certain other chemicals such as cadmium do stimulate collagen synthesis. The alveolar-like structures of lung cells in culture are pulmonary type II cells and contain lamellar bodies. Electron microscopy of these cultured cells indicates that they have the markers of pulmonary type II cells. In an attempt to determine what are the toxic chemicals in the coal leachates, chemical fractions of the leachate have been prepared. The cells respond differently to the chemical fractions of coal leachates. BIBLIOGRAPHIC REFERENCE: Christian Robert T. and Nelson, June. Coal: Response of Cultured Mammalian Cells Corresponds to the Incidence of Coal Workers Pneumoconiosis. Environmental Research, in press, 1977.